From the U.S. Pat. No. 5,356,420 a puncturing device is known comprising a sleeve and a push button positioned at one sleeve end. The other sleeve end terminates with a bottom with an opening therein. Inside the sleeve a piston is slidably positioned, terminating with a push rod at the end closer to the push button, and with a puncturing tip at the end closer to the bottom opening. Inside the sleeve, between the push button face and the piston a drive spring is located, and between the piston and the sleeve bottom a return spring is placed. The piston comprises wings located on its outer perimeter, which wings rest on an internal projection of the sleeve, and when the device is used, the wings get broken, and subsequent re-use of the device is not possible.
In the U.S. Pat. No. 5,439,473 is disclosed a lancet designed for puncturing the patient's skin for collecting small blood samples. The lancet has an elongated body wherein a movable member is placed slidingly along the body axis, while the body has a top opening for the lancet push button, and a bottom opening for the piercing blade. The movable member consists of a flat spring, one end of which is joined to the push button. The push button has two upper arms perpendicular to its surface, and these arms have hooked ends placed in oblong openings of the body side walls. The other end of the movable member flat spring is joined with a holder wherein the piercing blade is fixed. The lower portion of the holder has two lower arms parallel to the upper arms. The lower arms have, moreover, upwardly directed, triangle shaped ends, which rest upon the lower edges of the oblong openings of the body walls. All parts of the movable member are made of plastic.
When the patient's skin is being punctured, the lancet push button is pressed, so the flat spring of the movable member is tensed, and hooked ends of the upper arms press against the ends of the lower arms of the movable member. Next, the lower arms get released, the flat spring rebounds, and the patient's skin is punctured by the piercing blade, which passes through the body bottom opening. After puncturing the skin, the flat spring assumes its free position, and the piercing blade retracts into the inside of the lancet body.
In the U.S. Pat. No. 4,616,649 is presented a disposable lancet unit built of a housing constituting at the same time a slideway for therein positioned a lancet body, whereas to one end of the lancet body a flat lancet is attached, while to the other end a push button is attached. Moreover, the housing has a plurality of separated from each other first integrated protrusions, which are directed inwardly inside the housing, and a plurality of separated from each other second integrated protrusions on the lancet body to mate with the first protrusions, and spring elements integrated with the lancet body, while the spring elements are placed between the lancet body and the housing.
Moreover, from the U.S. Pat. No. 5,527,334 an activating device is known for sequential sliding out and retracting a lanced needle in order to pierce the patient's skin to collect a sample of blood, and the device includes the lancet needle body comprising a connecting member attached to the needle holding member, a housing containing the lancet needle body inside, and an opening to slide out the lancet needle through it, a first slideway in the housing for reciprocal movements of the needle member to slide out and retract it through the opening, and the second slideway of the housing to direct the driving motion of the connecting member of the lancet needle body. The device, moreover comprises a breakable and removable needle sheath formed on the needle holding member, and twisting elements to perform the required twisting motion of the breakable needle sheath in order to remove the sheath part, after breaking it out, from the needle holding member.